dbcve.org
TomcatWeb server / proxy · Apache

CVE-2025-66614

CRITICAL · 9.1 CVSS v3.1 Published 2026-02-17
Fix available
A fix is available. Upgrade to 9.0.113 / 10.1.50 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper Input Validation vulnerability. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0-M1 through 9.0.112. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Older EOL versions are not affected. Tomcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one of those hosts did not require client certificate authentication but another one did, it was possible for a client to bypass the client certificate authentication by sending different host names in the SNI extension and the HTTP host header field. The vulnerability only applies if client certificate authentication is only enforced at the Connector. It does not apply if client certificate authentication is enforced at the web application. Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fix the issue.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Apache Tomcat fails to validate that the hostname in the SNI extension matches the hostname in the HTTP Host header. This allows an attacker to bypass client certificate authentication on TLS connections by sending different hostnames in SNI and HTTP headers when multiple virtual hosts are configured with differing authentication requirements.

MitigationUpgrade to Tomcat 11.0.15+, 10.1.50+, or 9.0.113+ to fix the input validation, or migrate client certificate authentication enforcement from the Connector to the web application layer.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TomcatWeb server / proxy
Affected:>= 9.0.1, < 9.0.113>= 10.1.1, < 10.1.50>= 11.0.1, < 11.0.15= 9.0.0= 10.1.0= 11.0.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Apache Tomcat version
    Check the serverinfo.properties or RELEASE-NOTES file in the Tomcat installation directory, or run: java -cp catalina.jar org.apache.catalina.util.ServerInfo
    Affected if The installed version is 9.0.0 through 9.0.112, 10.1.0 through 10.1.49, or 11.0.0 through 11.0.14
  2. Verify TLS connector with client certificate authentication is configured
    Examine the server.xml file and look for <Connector> elements with SSL enabled (such as SSLEnabled="true" and a certificateKeystoreFile attribute). Check if the clientAuth attribute is set to "want" or "true"
    Affected if A TLS connector is configured that requires or requests client certificates (clientAuth="true" or clientAuth="want")
  3. Confirm multiple virtual hosts exist with differing authentication
    Review the server.xml file for multiple <Host> elements with different names, and check associated web.xml or context.xml files to see if client-certificate-based authentication (CLIENT-CERT) is configured differently across these hosts
    Affected if More than one virtual host is defined and at least one requires client certificate authentication while another does not, or they have different clientAuth settings
  4. Verify no application-layer certificate validation is enforced
    Check your web applications' web.xml descriptors and any servlet filters to determine whether client certificate validation is performed at the application layer rather than relying solely on the Connector configuration
    Affected if The application layer does not perform its own certificate validation and relies entirely on Tomcat's Connector-level clientAuth setting for authentication

You are affected if you run a vulnerable Tomcat version with a TLS connector requiring client certificates AND you have multiple virtual hosts where at least one enforces client certificate authentication while another does not, allowing an attacker to bypass authentication by mismatching SNI and HTTP Host headers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 9.0.113 / 10.1.50 / 11.0.15 or later
Fixed in 9.0.11310.1.5011.0.15
Interim mitigation

Upgrade to Tomcat 11.0.15+, 10.1.50+, or 9.0.113+ to fix the input validation, or migrate client certificate authentication enforcement from the Connector to the web application layer.

Recommended fix High confidence

9.0.113 (for 9.x users) | 10.1.50 (for 10.1.x users) | 11.0.15 (for 11.x users)

  1. 1. Back up your current Tomcat installation, configuration files, and deployed applications
  2. 2. Download the appropriate fixed version of Apache Tomcat (9.0.113, 10.1.50, or 11.0.15) from the official Apache Tomcat website
  3. 3. Stop the running Tomcat instance gracefully
  4. 4. Replace the Tomcat installation directory with the new version, preserving your configuration files (server.xml, context.xml, etc.)
  5. 5. Ensure any custom libraries or connectors are compatible with the new version
  6. 6. Start Tomcat and verify the service starts successfully
  7. 7. Test that your applications function correctly, particularly any that rely on client certificate authentication
  8. 8. Verify the fix by checking that SNI hostname and HTTP host header are now properly validated
Caveat Point releases typically maintain backward compatibility; however, review release notes for any deprecations or configuration changes before upgrading

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Tomcat Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,648.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-66614 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-66614 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data